Background: Recent advances in childhood acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL) management provide higher survival rates at the cost of increased toxicities. Acute neurotoxicity affects up to 10% of patients, requiring rapid recognition and treatment. Methods: A retrospective observational study was performed to determine the frequency, clinical manifestations, radiological characteristics, treatment options and outcome of acute neurological adverse events in pediatric patients with lymphoid malignancies at the Department of Oncology and Hematology, Children’s Hospital Zagreb, Croatia. Results: A total of 56 patients (48 ALL and 8 LL, male/female ratio 1:1, average age 5.4 years) were treated mainly according to the ALL-IC BFM 2009 protocol. The B-immunophenotype was the most frequent (85.7%). Most patients were stratified to the intermediate risk group (39.3%), and two were initially diagnosed with central nervous system infiltration. Acute neurotoxic events were registered in 11 patients (19.6%), most commonly in the 6–10-year age group (66.7%), predominately in females (72.7%) and high-risk group (54.5%). The most frequent clinical presentation was seizures (83.3%), with status epilepticus in four cases. We detected electroencephalogram (EEG) irregularities in almost all patients and various morphological changes in the brain magnetic resonance imaging (MRI), most often consistent with posterior reversible encephalopathy syndrome and leukoencephalopathy. Approximately half the patients received prolonged antiepileptic therapy. No apparent residual neurologic manifestations have been observed. Conclusions: Acute neurotoxicity is a rather frequent treatment-related adverse event, associated with high-risk disease. Early recognition and timely management are essential for rapid recovery and optimal outcomes.

Malnutrition is often observed in pediatric cancer patients and has been recognized as a risk factor for relapse and survival. Maintaining an appropriate nutritional status during anticancer treatment has, therefore, been more and more frequently perceived as an additional requirement for optimal therapy outcomes. The aim of our study was to establish alterations of nutritional status in 26 children and adolescents treated for acute lymphoblastic leukemia (ALL) at the Children’s Hospital in Zagreb, Croatia, between 2016 and 2021, by using anthropometric measures and serum albumin levels. The majority of patients (53.8% female, median 4 years, 52.2% intermediate-risk leukemia group) had normal weight at the beginning of chemotherapy. The percentage of overweight/obese patients increased from 4.2% at diagnosis to 37.5% at the end of intensive therapy. Apart from a significant increase in body weight (BW) and body mass index (BMI) for age, a notable decline in body height/body length (BH/BL) for age in the observed period was recorded, especially in high-risk leukemia patients. The alterations in serum albumin values were not significant, nor was their correlation with BMI. Dietary consultation was offered to all patients, while children with a decline in BMI and BH/BL received additional nutritional support.

Iron deficiency anemia (IDA) continues to be a global public health concern, mostly in the developing countries. However, precise epidemiological data on childhood IDA in Croatia are lacking. In order to establish its frequency, underlying etiologies, the rationale for tertiary care visits, diagnostic practices, and current treatment regimens of IDA, medical records of children referred to pediatric hematologists for iron deficiency in a five-year period at tertiary institutions (Zagreb, Rijeka, Split, Osijek) throughout Croatia were retrospectively analyzed. Eight hundred and sixty-four children, predominately of preschool age, were referred mainly by the primary care pediatricians, who, in general, performed basic diagnostics but failed to initiate oral iron therapy in half of the patients. Approximately one-third of patients were symptomatic, with inadequate nutrition prevailing as underlying etiology. Dextriferron was the preferred iron formulation among hematologists, with a median dose of 5 mg/kg, with acceptable compliance rates (63.5–93.2%). Hospital admission rates varied among the centers (9.4–35%), and so did transfusion policies (6.4–22.9%). The greatest difference was observed in the frequency of parenteral iron administration (0.3–21.5%). In conclusion, the burden of childhood IDA, even in a high-income country, remains substantial, necessitating consistent implementation of national guidelines and additional education of primary health care providers.

Nutritional status is recognized as an independent and modifiable risk factor of outcome in stem cell transplant. Our research aim was to evaluate the impact of body mass index (BMI) and serum albumin on the prevalence of adverse events and survival in autologous transplant in children. A retrospective study was conducted of autologous transplants performed between 2006 and 2017 in the Children's Hospital Zagreb, Croatia. Nutritional status was assessed at the times of diagnosis, procedure, and discharge using BMI (underweight, normal, obese) and serum albumin (grades 1-4). Adverse events (fever, gastrointestinal toxicity, electrolyte disturbances, dysglycemia) and outcome (3-year, relapse, mortality) were documented. Seventy-seven children (54.5% males, mean age 7.9 years) underwent autologous transplant, mostly for neuroblastoma. In terms of BMI and albumin, which showed significant positive correlation at diagnosis (p = 0.026) and transplant (p = 0.016), most participants were well nourished. Average post-transplant weight loss was 4%. Major toxicities were severe mucositis (72.7%) and hypophosphatemia (31.2%). Relapse and mortality rates were 35.1% and 42.9%, respectively. Hypokalemia (p = 0.041) and hypomagnesemia (p = 0.044) were more prevalent in the underweight group, while obese children experienced significantly less severe mucositis (p = 0.016) and hypophosphatemia (p = 0.038). There was no significant difference regarding outcome among children of different nutritional status, although undernourished children tended to have lower relapse and mortality rates. In conclusion, underweight children are significantly more prone to severe electrolyte disorders and mucositis, and although statistical significance was not reached, are more likely to survive.

Background: Adolescents and young adults diagnosed with acute lymphoblastic leukemia are treated according to pediatric-based regimens to achieve better results. However, implementation of intensive chemotherapy protocols in this age group is associated with increased treatment-related toxicities, affecting almost every organ and system. In this case, the focus of our interest was on rather rare entities: steroid-induced psychosis that seldom develops in children and adolescents, and choroid plexus hemosiderosis, infrequently identified as a first sign of iron overload.Case presentation: The aim of this paper is to present a challenging case of a 15-year-old Caucasian male patient treated for high-risk acute lymphoblastic leukemia and who experienced various adverse incidents during intensive chemotherapy, thus necessitating a high-quality multidisciplinary approach. Slow minimal residual disease clearance was an additional concerning issue. Induction and re-induction were complicated by steroid-induced hyperglycemia that required multiple-week insulin. During consolidation, acute kidney injury on the basis of chronic kidney disease was verified, demanding subsequent drug dose modifications. By the end of re-induction, after dexamethasone cessation, infrequent steroid-induced psychosis, presented as incoherent speech, aggressive behavior, and mood swings, required intensive psychiatric support. Neurological evaluation of seizures revealed uncommon choroid plexus hemosiderosis by brain magnetic resonance imaging, warranting appropriate selection of iron chelation therapy in the context of preexisting nephropathy. Ultimately, iron deposits of moderate intensity were verified by liver magnetic resonance imaging, while heart tissue remained intact. The early diagnosis and adequate treatment of aforementioned difficult toxicities resulted in complete recovery of the patient.Conclusions: Treating adolescents with high-risk acute leukemia and multiple therapy-related morbidities remains a challenge, even in the era of extensive and effective supportive therapy. Superior survival rates might be achieved by prompt recognition of both frequent and rarely encountered adverse episodes, as well as well-timed and appropriate management by a well-coordinated multidisciplinary team.

Introduction: The use of complementary and alternative medicine (CAM) has become a customary practice among pediatric cancer patients worldwide. The frequency of its use by pediatric cancer patients in Croatia has not been previously determined. Methodology: In order to establish the frequency and detect factors affecting the use of CAM, a single-center, observational, cross-sectional study was conducted at the Children's Hospital Zagreb during a two-year period. The patients' parents and caregivers were offered an anonymous, multi-item questionnaire that collected socio-economic and clinical data, as well as details on CAM and dietary supplement practice. Results: Almost half of the participants reported CAM and more than two-thirds reported dietary supplement consumption, predominantly in the intensive phase of the treatment. Factors regarding children or parents had no effect on CAM and supplement utilization. Herbal medicine, vitamins, and minerals were among the most commonly used items. Every 10th child experienced at least one adverse event during CAM and supplement use. Conclusion: Awareness of the CAM and dietary supplement application in pediatric oncology patients needs to be raised due to the potential interactions with conventional treatment modalities. For this reason, it is extremely important to inform parents and caregivers of pediatric oncology patients about the use of CAM and dietary supplements to predict and mitigate the occurrence and intensity of the side effects. In the majority of our cases, the patient's guardians informed the healthcare professionals about the CAM and supplement implementation in their children, therefore, they were offered additional information about the possible negative impact of CAM and supplement use on standard medical care in a timely manner.